The invention relates to a method for manufacturing fuel briquettes from refuse such as garbage, whereby the refuse is sorted so as to separate out the components thereof which are to be used for briquettes.
The increase in affluence has resulted in problems for society regarding the handling and treatment of the steadily increasing amount of garbage. This has generated environmental problems which include the pollution of land when storing the garbage, and airpollution when combusting the garbage. Refuse from garbage consists of inflammable and non-inflammable components. The non-inflammable parts are largely iron and glass, and comprise about 5 weight% of the garbage. The rest, about 95 weight%, is usually combusted in a refuse incinerator where a large amount of primary fuel has to be added in order to combust the often moisty and nonhomogenous garbage. The result is a low heating efficiency, partly because diversified garbage is difficult to burn, and partly because the garbage is currently burned without considering the heat which is gained from the combustion in the form of steam in district heating plants.
Since garbage can not be directly stored for a long period without putrefying, it has to be burned off immediately upon collection. Thus, the heat from the district heating plant is not utilized optimally outside the heating season, resulting in waste of heat. In addition, the garbage must be brought to a refuse destructor plant which is connected to a district heating plant in order to utilize the calorific value for district heating.
English Pat. No. 1.286.532 describes a method for manufacturing fuel briquettes from garbage. By this method, metal pieces and dust are first removed, and the garbage is crushed into smaller pieces which are thereafter dried. The dried, comminuted garbage is mixed with crushed coal, and a binding material is added prior to the briquetting. After this procedure, the briquettes must be heat-treated for up to 3 hours at a temperature range of about 200.degree. C. before they are ready for use as fuel briquettes.